How many protons does calcium have?

Atoms of two adjacent elements in the third period are in the ground state. An atom of element A has only s electrons in its valence shell. An atom of element B has at least one p electron in its valence shell. Identify elements A and B.

If you were to pour 4 different liquids into a glass and the liquids separated into 4 layers, which liquid would have the highest density? A. the layer at the top of the glass B. the third layer from the bottom of the glass C.

Which statement best explains the plateau seen in the cooling curve of naphthalene? A) The energy of the system decreases B) The temperature of the system increases C) the temperature of the system decreases D) The energy of the system remains

4AI+30 2 > 2AI2O3 What id the chemical reaction?

A student explained to the class that helium has 8 valence electrons because it is in group 18. Is the student correct? - The student is incorrect because helium has 2 valence electrons and it's in group 18 because the first energy level is full.

How to assign oxidation and reduction numbers

How to tell difference between hydrogen gas and oxygen gas?

Why do atoms have different speed

Jose gets up from his seat on the bus to move closer to the front. Just as he begins to walk forward, the bus stops at a light.

How would you present weight change if Earth had twice the mass that it does